EF0 is the weakest point on the Enhanced Fujita scale and EF5 is the strongest.

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Both years saw major storms (F4 or F5 on the F0-F5 Enhanced Fujita scale) plow very long paths through densely populated territory.

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The tornado was estimated to be an EF-5, the most devastating on the Enhanced Fujita Scale, with wind speeds exceeding 200 mph.

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The National Weather Service issued an initial finding that the tornado was an EF-4 on the enhanced Fujita scale, the second most powerful type of twister.

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The Tuscaloosa tornado was later given a rating of EF4, the second-most powerful on the Enhanced Fujita Scale, meaning it had wind speeds between 166 and 200 mph.

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Tornados are rated on several scales for strength based either on wind speed, pressure drop, or damaged caused, but the updated Enhanced Fujita Scale is the presently accepted scale in the United States.

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